Work holding mechanism



April 18, 1933. LOVELY 1,904,152

WORK HOLDING MECHANIM Filed June 28, 1930 2 Sheets-Sheet l i? waxa April 13, 1933- J. E. LOVELY 1,904,152

WORK HOLDING MECHANISM Filed June 28, 1930 2 Sheets-Sheet 2 flea?? J67WaZ 1 Z02/eg .zOy

Patented Apr. 18, 1933 Jenn E. ,LovELY, or SPR NG E D; VERMONT, nssienon 'ro JONES ,& IAMson MACHINE COMPANY, or SPRINGFIELD," VERMONT, nc'onronn'rron or vngamronr wonx nonnme Mechanism Application filed June 28,

of the spindle, and is centered for such clamping and is clampedby means movable axiallyof the spindle, which, when in work releasing position, is retracted axially of thespindle out of transverse alinement with the work; The work carried is provided with a 1 central bore within which the work-engaging mechanism may engage, work such as tubular work being well adapted to be held by th s mechanism.

For a more complete understanding of this invention, reference may be had to the accom panying drawings in which Figure 1 is a fragmentary front elevatlon a of a lathe embodying such a mechanism, the 25 work being shown in position. 7 Figure 2 is a section to a larger scale substantially on line 2-2 of Figure 3..

Figure 3 is a section on line 33 of- Figure 1; e i 36 Figure 4 is a view similar to a portion of Figure 2, but showing the worksreleasedposition of the parts. V Y

Figure 5 is a section on line 55 of Fig ure 2. V v Figure 6 is a. section on line 6-6 of Figure 1.

Figure 7 is a view somewhat similar to Figure 6, but showing the tailstock plunger in elevation in work-released position.

Figure 8 is a View to a larger scale similarto a portion of Figure 6. V

Figure 9 is a diagrammatic View of the fluid pressure motor actuating the headstock.

Figure 10 is a disassembled view of the :45 headstock work centering and gripping mechanlsm.

Referring to Figure 1, at 1 is indicated the bed portion of a lathe having a headstock at 2 and a tailstock at 8. As shown in Figures 6, 7

" and 8, the tailstock 3 has a tubular portion 5 1930. Serial 110.464.,471.

within which is axially slidable a sleeve 6. having suitable bearings as at 7 and 8 to receive a tailstock spindle 9. This tailstock spindle is shown asprovided with a tapered pilot portion which is arranged toenter the opening in a hollow or tubular piece of work 1-2, to properly center one endas is shown in Figures 6 and 7. The sleeve 6 is mounted for axial movement within thetubm lar portion 5 and may be given such move;- ment by means of a stem connected to a piston member 16 operating ina fluid pressure cylinder 17 ofusual construction. By admitting fluid under pressure, asthrough the pipe 18, the plunger 6' and the pilot -10 are retracted, the fluid pressure exhausting 7 through the pipe 19.

By admitting fluid under pressure through the pipe 19 and ex hausting through the pipe 18, the; sleeve 6 and the pilot 10 are movedin the opposite direction. This outwardmovement of the pilotlOis employed to press the-work 12 against a 'memberon the headstock". This member, as shown best in Figures 2and 4, is-

a tubular member having a work-receiv ing and stops-plate 26 on its forward end against which the work directly engages. V I The tubular member 25, asshown, is pro-- vided with an annular flange 27 at its rear end by which it may besecured in any suitable manner to a spindle nose 28 of the lathe. As shown this securingmeans comprises bolts, one of which is indicated at 29, passing through the flange 27 and threaded into an opening 30 in the spindle. nose. At 31Qis shown a key piece secured to the nose 28, which rides in a depression in the flange 27;, thus to key the nose and member 25 for simul taneous rotation The member :25 and its stop plate portion 26,.which are rigidly fixed togethemas by means such as screws 32, are thus arranged in axial lathe spindle35. w

Positioned within the member 25 is anele-l ment 4:0 slidably guided for axialmovement diameter por'tion 4flextending between an alinement with the.

annular shoulder at its inner end and the inner face of a locating or pilot head 46 at its outer end. This portion 44 is tapered with its small diameter end adjacent to the head 46. This head 46 acts as a pilot entering the opposite end of the hole in the work 12 from the tailstock pilot 10. i

Arranged about the tapered portion 44 aresegmental parts 50 having their inner.

faces mating the taper of the portion 44, these parts being of less length thanthe portion 44 so that they may be moved axially thereof. When they are positioned adjacent to the head 46, their outer faces are in contracted position, in which position they are free to enter thehole in the work 12 with the pilot portion 46, and they are normally held in this position, as by means of spring pressed plugs 51 seated in sockets 52 in the member 40. The outer ends of the plugs 51 are flattened to engage in 'suitable'slots 55 in the rear ends of the segmental parts 50. These segmental parts are thus held keyed againstrelative rotation with respect to the element 40. The element 40 is shown as-connected to an actuating rod 60, which as indicated diagrammatically in Figure 9, forms the piston rod of a fluid pressure motor having a cylinder 61.

When fluid pressure is admitted to the outer endof this cylinder, it is also admitted to the outer'end of the cylinder 17 at the tailstock end of the machine. This causes the tailstock to be advanced toward the headstock, causing the pilot 10 to enter the hole in the work and clamp the work against the member 26, while atthe same time the member 40 is actuated to project its head end into the opposite end of the work and to carry therewith the outer ends of the segmental members 50. This takesplace until thefur-. ther motion of the segmental parts 50 is stopped by reason of annular shoulders 62 thereon contacting with a mating shoulder 63 on the stop member 26. Continued movement of the member 40 thus causes the larger diameter end of the portion 44 to passbetween the segmental members, thus forcing them apart and into clamping engagement with the inner wall of the work opening.

When the air control valve 65 is manipulated to exhaust fluid pressure from .the outer ends of the cylinders 17 and 61 and to admit fluid under pressure to the inner ends of these cylinders, the pilot portions are withdrawn,

the element 40 being retracted within its tubular housing portion, as shown in Figure 4, and the pilot 10 being retracted sufiiciently to free the work from the endof the stop member 26, whereupon the work is free to drop out from between the head andtailstocks. The headstock mechanism, may, if desired however, be used without the tailstock. j i i From the foregoing descriptionof an embodiment of this invention, it should be eviflange for attachment to a lathe spindle nose coaxially with said spindle, an element movable axially within said member to be retracted thereinto or to project from said member within an opening in work placed against said member, parts movable with said element for engagement with the wallof said opening, and a stop for limiting the projec tion of the parts to less than the full extent of projection of said element, said element and parts having cooperating portions causing further projecting movement of said element after said parts are stopped to press said parts outwardly into engagement with said .wall.

2. A mechanism of the class described comprising a tubular member, means for attach-.

mg said member to a lathe spindle in axial alinement therewith, an element having a.

shoulder and slidable axially within said member and having a conical head at its outer end and tapered portion back of said head, its small diameter portion being adj acent thereto, said tapered portion being positioned outwardly of said shoulder, parts .ar ranged about said tapered portion having inner faces mating the taper thereof, said parts being of less lengththan said tapered portion, means for yieldingly holding said parts pressed about said head so that their outer faces are in contracted position a tubular stop for limiting the'outward movement of said parts with said element, means for holding tubular hollow work against said stop with its opening positioned to receive said element, and means for projecting said element to cause its head to enter the work and center the same, and said parts to first enter the work and then to spreadthereagainst as said element is projected further after said parts contact with said stop, and for retracting said element to first relieve the clamping pressure of said parts thereagainst and then to withdraw said parts and element from the hole in the work.

3. A mechanism of the class described com-- 4. A lathe having head and tailstocks, a tubular member carried by said headstock in axial alinement therewith, means in said tubular member projectable to engage the inner wall of tubular work positioned thereagainst, fluid pressure means for projecting and retracting said engaging means, fluid pressure means for moving said tailstock toward said headstock to press the work against said member or away from said headstock to re.- lease the work, and a control device common to both of said fluid pressure means.

5. A mechanism of the class described, comprising a pair of oppositely disposed elements movable toward and from each other to clamp tubular work therebetween, one of said elements being tubular, and means retractable axially within said tubular element and projectable axially therefrom and outwardly into clamping engagement with the inner wall of the work.

6. A lathe having head and tailstocks, a tubular member carried by said headstock in axial alinement therewith, means in said tubular member projectable axially therefrom and outwardly to engage the inner wall of tubular work positioned thereagainst, means for projecting and retracting said engaging means, means for moving said tailstock toward said headstock to press the work against said member or away from said headstock to release the work. and a control device common to both said projecting and retracting and said tailstock-moving means.

7 A mechanism of the class described comprising a tubular member against an end of which work may be engaged, an expa-nsible and contractable work engaging means movable axially within said tubular member, and means actuable to project said work engaging means from said end and to retract said work engaging means into said member, said mechanism including means for expanding said work engaging means to engage the inner wall of hollow work engaging said end when said engaging means is so projected.

8. A mechanism of the class described comprising a tubular member against an endof which work may be engaged. an expansible and contractable work engaging means movable axially within said tubular member, and means actuable to project said work engaging means from said end and to retract said work engaging means into said member, said projecting means including means acting on said work engaging means to expand it into engagement with the inner wall of hollow work engaging said end when said engaging means is so projected.

9. A mechanism of the class described comprising a tubular member against which the end of hollow work may be placed, work engaging means movable axially in said tubular member and retractable entirely within signature.

JOHN E. LOVELY. 

